The authors gratefully acknowledge funding of this research by the US-DOE Basic Science Office under Contract DE-FG02-10ER46406.
Applied Physics Letters
Optical diffraction, Photoelectron spectroscopy, Nanostructures, Electric fields, Wavelengths
We report the visualization of optical diffraction at the boundaries of semiconductor and metal nanostructures in non-linear photoemission electron microscopy. We observe light diffracting into photonic and plasmonic modes of planar samples, and into photonic vacuum modes above sample surfaces. In either case, the electron photoemission rate from the sample material is spatially modulated resulting in photoemission images with information on the electric field distribution at the sample/vacuum interface. The resolution in these images is typically ∼30 nm, i.e., significantly below the wavelengths of the exciting light. Optical phase shifts and absorption losses for the diffracted modes can be determined.
Word, Robert C., J. P. S. Fitzgerald, and Rolf Konenkamp. "Direct imaging of optical diffraction in photoemission electron microscopy." Applied Physics Letters 103.2 (2013): 021118-021118.